Answer:
20/81
Explanation:
The total number of brownies is 2 + 2 + 5 = 9. The probability of Gavin taking a brownie with nuts on the first pick is 5/9. After putting it back, the total number of brownies is still 9, but the number of brownies with nuts is now 4. Therefore, the probability of Gavin taking a brownie without nuts on the second pick is 4/9. The probability of both events happening together is the product of the individual probabilities: (5/9) x (4/9) = 20/81. Therefore, the probability that Gavin will randomly take a brownie with nuts, put it back, and grab one without nuts is 20/81.